Ladder lock buckle can also be called tension lock. This kind of lock can be adjusted from both ends to adjust the belt to the appropriate length and prevent sliding.
TensionLock - Ladder Lock - Hofman Outdoor Gear Supply
BOSWOAK Ladder Lock Slider,Heavy Duty Plastic Ladderlock Slider
Adjustable Buckle, Square Loop
Tensionlock - Ji-Horng Plastic Co., Ltd.
1 and 1/4 inches (32 mm) - Ji-Horng Plastic Co., Ltd.
Multi-Size Dual Adjustable Plastic Side Release Buckle for
Heavy-duty Plastic Buckles - Ji-Horng
10-100 Pcs 1.5'' Heavy Duty Black Plastic Ladder Lock Buckle Strap
CooBigo 50Pack 1 Plastic Black Ladder Lock Slider Adjustable
, Black, 0.75in,1in,1.25in,1.5in,2inch : : Tools & Home Improvement
BOSWOAK Ladder Lock Slider,Heavy Duty Plastic Ladderlock Slider Adjustable Lock Ladder Slide Buckle Adjuster for Backpack
Multi-Size Dual Adjustable Plastic Side Release Buckle for
CooBigo 50Pack 1 Plastic Black Ladder Lock Slider Adjustable
Non Adjust Side Release Buckle - Ji-Horng Plastic Co., Ltd.