Galvanised Trench Grate and Frame All grate & frames come in 2 metre sections. Code Measurements (all sizes in mm) Class GS1CFL 150 × 25 C GS3BFL 230 × 25 B GS5DFL 210 × 32 D GS6BFL 300 × 25 B GS7BFL 300 × 32 B GS8DFL 310 × 40 D GS3BFL with Lockdown Bolt