What does it mean to me as an investor when public mutual offers 1% free units

Well if you as an investor invest RM50,000 and the current selling price of the fund is 25 cent per unit. What you will get is:

RM 50,000 ÷ RM0.25 = 200,000 units
1 % Free units = 2,000 units

Total units that you as an investor will get is 202,000 units. The total cost of your investment will go down to:

RM 50,000 ÷ 202, 000 = 0.2475 cents per unit

So those who take this opportunities to invest will reap attractive capital gains on his "enlarged" unit holdings when there is a market upturn.