Tubolito Tubo TPU Innertube MTB. 29"/27.5" 1.8-2.5" Presta 42mm SV. That is where the best TPU inner tubes can make a big difference. While they don't quite improve rolling resistance to the levels of latex or the best tubeless tyres, they are very close and are a far more rounded option.
eBay
NPY 1Pcs Ultralight 28g Bike TPU Inner Tube 700X18 25 28 32 Road Bicycle TPU Material Tire 45mm/65mm/85mm Length French Valve
Aliexpress UK
Support 700C gravel bike, 35C-45C, 35C.38C, 37C, and 700C x32C, 700x47C, 700x50C, 700x48C, MTB 29x1.5 29x1.75 29x1.95. Before installing the outer tire, check whether the inner tube is leaking2pcs Ultralight 700C Gravel.
eBay
CYCLAMI Metal Material French Presta Valve Ultralight Bike TPU Inner Tube Road Bicycle TPU Material Tire Length 700C 700 x 18 28
Aliexpress UK
Material:TPU+ Alloy.
eBay
BKPTX 1Pcs 28g Ultralight Bike TPU Inner Tube 700X18 25 28 32 Road Bicycle TPU Material Tire 65mm Length French Valve
Aliexpress UK
For tire width Highway 700C 700x18/23/25/28/30/32. Pacakge Include: 1 Bike TPU Inner Tube. Material: TPU. For tire width Highway 700 18C 23C 25C 28C 30C 32C. Suitable for bikes with rim brakes and disc brakes.
eBay
BKPTX 1Pcs/2Pcs 28g orange Bike TPU Inner Tube 700X18 25 28 32 Road Bicycle TPU Material Tire 65mm Length French Valve
Aliexpress UK
2 TPU presta valve (60mm) tube. 2 tubes in your back pocket and two in your tyres, that's 1/2 a KG weight saving. TPU are easily repairable. Like with a buytyl tube unless it is right next to the valve I fix and re-use mine.
eBay
Ridenow MTB Bicycle TPU Inner Tube 26inch/27.5inch/29inch Ultralight Mountain Bike Inner Tire French Metals Valve Length 45mm
Aliexpress UK
Ultralight Tubolito tubo style TPU tubes weighing only 25 grams. 3x lighter than a standard tube! Before inflating the CYDY tube, turn the valve inward (towards the center of the tire circle). Suitable for 700c tyres from 18mm to 28mm wide.
eBay
CYCLAMI 2 pcs Bike Tyre Pry Bar ROAD MTB TPU Inner Tube Tube Remover Tool Ultralight Wheel Repair Tool Cycling Accessories
Aliexpress UK
For tire width Highway 700C 700x18/23/25/28/30/32. Qty:4/8Pcs optioanal. 4/8Pcs Bike TPU Inner Tube. Material: TPU. For tire width Highway 700 18C 23C 25C 28C 30C 32C. Suitable for bikes with rim brakes and disc brakes.
eBay
GUSTAVO MTB Bike TPU Inner Tube ,Ultralight Mountain Bicycle Tire Tubes, 26 27.5 29 X 1.95-2.8 , Presta Valve 45MM
Aliexpress UK
Support 700C gravel bike ，35C-45C ，35C.38C，37C，and 700C x32C,700x47C ,700x50C，700x48C ,MTB 29x1.5 29x1.75 29x1.95. Ultralight design，only 46g，Lose weighton your tires，Reduced spinn mass where there are more(wheelsets).
eBay
Mountain Bicycle TPU Inner Tube Ultralight Cycling Bike Tire Tubes 20(406) 26 1.35-2.6 27.5inch French Valve 45/65MM
Aliexpress UK